CN102931130A - Method for repairing ashed side wall - Google Patents

Abstract

The invention discloses a method for reducing effective dielectric constant existing between two conducting assemblies of an integrated circuit. The method relates to the use of gas-phase etching, and the gas-phase etching is selective to an oxygen enrichment part of a low K dielectric layer; the etching rate is weakened when the etching technology reaches to a low K part by passing through a high K oxygen enrichment part; and the needed low K part is not easy to remove by the gas-phase etching technology, and thus the control of the etching technology can be easily realized.

Description

The ashing rear wall is repaired

Technical field

The application relates to a kind of method of making semi-conductor electronic device.

Background technology

Method for manufacturing integrated circuit has reached generally and has formed several hundred million transistorized degree at one single chip.The manufacturing technology of every kind of a new generation and equipment are being realized less faster transistorized commercial large-scale production, but have also increased the difficulty of making less faster circuit element.The dwindling of size of circuit (now fully below the 50nm threshold value) caused the chip designer to seek new low resistance conductive material and new low-k (namely, low K) insulating material improves the electrical property of (or in simple terms, keeping) integrated circuit.

Along with the increase of each regional number of transistors, parasitic capacitance becomes the remarkable obstacle of transistor switch speed.Electric capacity is present between the conductor of all adjacent electric insulations in the integrated circuit, and no matter current-carrying part is positioned at " front end " or " rear end " of manufacturing process flow, but electric capacity limit switch speed all.

Thereby, need new technology and material between adjacent conductor, to form low-K material.A class material that is used for providing low K to separate between conductor is the organosilan film of oxidation, such as the Black Diamond that can obtain from the Applied Materials (Applied Materials, Inc.) in the Santa Clara city of California, USA on the market ^TMFilm.These films have the dielectric constant lower than conventional interval insulant (such as Si oxide and nitride) (for example, about 3.5 or lower).Regrettably, some new techniques relate to low K film are exposed to the environment that may improve effective dielectric constant, have limited device performance.

Thereby, need to after being exposed to these environment, low K film keep the new technology of lower effective dielectric constant.

Summary of the invention

The invention describes the method for reducing the effective dielectric constant between two conductive components that are present in integrated circuit.Described method relates to the use vapor phase etchant, and described vapor phase etchant partly is optionally for the oxygen enrichment of low-K dielectric layer.When described etch process passed relatively high K oxygen enrichment and partly arrives low K part, etch-rate weakened.Because described vapor phase etchant technique is not easy to remove required low K part, so the time that is easy to is controlled described etch process.

Embodiments of the present invention comprise the method for the effective dielectric constant that reduces low-k dielectric materials, and described low-k dielectric materials is between two grooves on the patterned substrate, and described patterned substrate is in basement processing area.Described low-k dielectric materials consists of the wall of described two grooves.Described method comprises to be transferred to described patterned substrate in the described basement processing area.Described method further comprises carries out vapor phase etchant to described patterned substrate, with by removing the average dielectric constant that outside dielectric layer reduces described low-k dielectric materials from described low-k dielectric materials.

To partly set forth in the following description other execution mode and feature of the present invention, and according to this specification, part will become apparent to those skilled in the art, perhaps can understand from the practice of disclosed execution mode.Can realize and obtain purpose and the advantage of disclosed execution mode by means, combination and the method for describing in this specification.

Description of drawings

The characteristic that can realize disclosed execution mode by remainder and the accompanying drawing of reference specification and the further understanding of advantage.

Figure 1A-1B is the cross-sectional view in gap during processing according to described open execution mode.

Fig. 2 is the flow chart that removes technique according to the photoresist in the filling gap of described open execution mode.

Fig. 3 is the cross-sectional view according to the process chamber of described open execution mode.

Fig. 4 is the treatment system according to described open execution mode.

In the accompanying drawings, identical assembly and/or feature have identical reference marker.In addition, the various assemblies of same type can be by being distinguished by the second mark of dash and these same components of differentiation behind reference marker.If only use the first reference marker in specification, then described description is applicable to have any one identical assembly of identical the first reference marker, and no matter the second reference marker how.

Reference numeral in the accompanying drawing is as follows:

110 low-K materials

120 photoresists

The 125SiCN layer

The 210-245 operating procedure

300 process chambers

302 cap assemblies

304 supporting component passages

310 supporting components

312 Room main bodys

313 Room body passageways

320 gas delivery boards

322 annular mounting flanges

325 vacuum pumps

327 choke valves

329 pump channels

330 stopper assemblies

331 vacuum ports

333 linings

335 openings

340 processing regions

345 electrodes

346 power supplys

347 electrical insulation rings

350 top boards

351 openings

352 openings

360 slit valve opening

The 361-363 zone

370 heating elements

400 treatment systems

The 402-404 load lock chamber

410 first manipulators

The 412-418 process chamber

The 422-424 transfer chamber

430 second manipulators

The 432-438 process chamber

455 gas handling systems

457 system controllers

Embodiment

The invention describes the method for reducing the effective dielectric constant that between two conductive components of integrated circuit, exists.These methods relate to the use vapor phase etchant, and described vapor phase etchant partly is optionally for the oxygen enrichment of low-K dielectric layer.Along with described etch process passes relatively high K oxygen enrichment part and arrives low K part, etch-rate weakens.Because described vapor phase etchant technique is not easy to remove desired low K part, so the time that is easy to is controlled described etch process.Vapor phase etchant is better than the fluid cushion oxide etching, is particularly suited for the pattern Processing substrate.Compare with liquid etchant, gas phase etchant is easier to be removed from narrow structure.

Embodiments of the present invention to increase effective dielectric constant, improve device performance for the method for the suprabasil low-K material of etched patternization thus.Can relate to from the exemplary process flow that the method that provides here is benefited two different photoetching-etched patterns are transferred to substrate.These techniques can be designed to base patternization twice, to obtain desired step rather than the conventional path with relative vertical wall in access structure.These process sequences can require the with photoresist substrate of coated pattern, thereby photoresist penetrates path and other gaps in the low-K material.Remove photoresist and generally comprise ashing, be about to described structure and be exposed to the oxidation precursor.When removing the photoresist of filling the gap, cineration step has also changed the sidewall in gap in the mode of the dielectric constant in the thin skin that increases low-K material.Some ashing relate to be exposed to the oxygenatedchemicals that is stimulated in plasmas.In these cases, oxygen is processed the surface oxidation that makes low-K material, and has increased oxygen content with respect to carbon content.In order to make the level before dielectric constant revert to its ashing, the method that proposes has here removed the material of the thinner relatively high K of this layer.

In order to understand better and understand the present invention, referring now to Fig. 1-2, Fig. 1-2 is according to disclosed execution mode, at the cross-sectional view of processing procedure intermediate gap and for the treatment of the flow chart in described gap.Structure shown in Figure 1A produces by photoetching-etching-photoetching-etch sequence, and in described photoetching-etching-photoetching-etch sequence, the second photoetching-etching step is opened wider groove in advanced low-k materials 110-1.The second etching only penetrates a part of path that arrives described channel bottom, stays step in low-K material 110-1.The above and below of described step is the wall of the approximate vertical that formed by low-K material.In disclosed execution mode, described wall may depart from mutually with the theoretical vertical line shown in Figure 1A-1B, but can depart from vertical 10 °, 5 ° or 2 °.After the second etching, some photoresists 120 are retained in the bottom of groove, and described photoresist 120 need to be removed before the gap-fill metal.When patterned substrate being transferred to process chamber (operating procedure 210), the technique that removes residual photoresist 120 begins.Oxygen base (oxygen-radical) air-flow is imported ashing chamber (operating procedure 215), and in groove, remove photoresist.In the example that Figure 1A illustrates, comprised fire sand (SiCN) layer 125-1, avoid spreading from the metal of subsurface material with protection low-K material 110-1.SiCN layer 125-1 also can lead to the peroxy modification, thereby removes the part SiCN at channel bottom place, obtains the SiCN layer 125-2 of patterning.Exemplary SiCN layer is the Blok that can obtain from the Applied Materials in the Santa Clara city of California, USA ^TMThere is in some embodiments the SiCN layer, and do not exist in other embodiments.Oxygen base air-flow also makes the wall oxidation of low-K material 110, has improved the dielectric constant of close surface (wall of groove) unexpectedly.Exemplary low-K material is silicon oxide carbide (SiOC), and exemplary SiOC product is equally can be from the Black Diamond of Applied Materials's acquisition ^TMIgnore formation and the continuation of oxygen enrichment (relatively high K) superficial layer and carry out the service area (operational regime) that gap-fill can limit resulting devices with the metal deposition groove.

Step below using, the low-K material 110 that dielectric constant weakens can almost return to the level before described low-K material 110 ashing.The substrate etching of the substrate of patterning being transferred to process chamber is regional, to be further processed (operating procedure 220).The air-flow of ammonia and Nitrogen trifluoride is incorporated into (operating procedure 222) in the plasma zone of separating with processing region.The plasma zone of described separation can be called the remote plasma body region here, and can be the module different from process chamber or the chamber in the process chamber.Remote plasma effluent (product of remote plasma) flows to process chamber and reacts (operating procedure 225) with substrate surface.Plasma flows out air-flow and the described surface reaction of thing, and producing solid residue, described solid residue comprises from the material of plasma outflow thing with from the material of the wall of the low-K material 110 that reacts.In exemplary environment division, be beneficial to the detailed chemical reaction of understanding this technique with providing.Then, by described patterned substrate is heated to more than the sublimation point of described solid residue, remove described solid residue (operating procedure 240).By removing described patterned substrate from described substrate etching zone, finished described technique (operating procedure 245), illustrate final structure among Figure 1B.

The etch-rate of outside dielectric layer is greater than the dielectric substance at the relatively low K of described outside dielectric layer inside.In embodiments of the present invention, the etch-rate of all the other low-k dielectric materials of vapor phase etchant speed ratio of outside dielectric layer exceeds the multiple greater than 25,50 or 100.In execution mode, the thickness of outside dielectric layer is approximately

Or less, be approximately

Or less, perhaps be approximately

Or less.

The illustrative processes of just having described is SiConi ^TMThe part of etching series, described SiConi ^TMEtching series relates generally to exist simultaneously the air-flow of fluorine-containing precursor and hydrogeneous precursor.In different execution modes, fluorine-containing precursor comprises Nitrogen trifluoride, hydrogen fluoride, diatomic fluorine, monoatomic fluorine and the hydrocarbon of fluorine replacement or the composition of above-mentioned material.In different execution modes, hydrogeneous precursor comprises atomic hydrogen, diatomic hydrogen, ammonia, hydrocarbon, the incomplete hydrocarbon that replaces of halogen or the composition of above-mentioned material.For for simplicity, some that comprise here discussion may be with reference to using the exemplary SiConi of ammonia and Nitrogen trifluoride combination ^TMEtching.Can use any SiConi ^TMEtching replaces describing and illustrated exemplary etching among Fig. 2.All SiConi that comprise fluorine and hydrogen (but substantially not having or do not have at all oxygen) ^TMEtch table reveals the selectivity stronger to etching oxidation silicon.These etch processs remove silicon, polysilicon and silicon oxide carbide very slowly.As a result of, even after the wall of low-K material 110 has consumed silica, proceed etching, SiConi ^TMStay the additional advantages of desired silicon oxide carbide low-K material 110 with still having basic perfect.Described selectivity be so that described technique can be subject to timing controlled, and need not use the evaluation of end point method of any other form.

Although example described herein is suitable for the double patterning (LELE) of low-K dielectric layer, need to the gap in low K layer in other technological processes of deposition photoresist also be possible.As a result, propose and claimed described method all effective in relating to any application of any gap filling material being carried out ashing, described gap filling material can remove self by oxidation processes.But the gap filling material of ashing comprises bottom or reflection coating provided (BARC or TARC) and various photoresist and other similar carbonaceous materials.In disclosed execution mode, but the gap filling material of ashing lacks in fact oxygen.But oxidation processes removes the gap filling material of ashing the modification of unexpected ground described wall, improved the dielectric constant in the superficial layer of modification.Can use method described here to reduce the dielectric constant of described raising.The profile of groove can comprise the ledge structure on trench wall as shown in Figure 1A-1B, but does not have in fact step in other disclosed execution modes.

As previously described, gap and groove are formed in the low-K material.Has step (seeing Fig. 1) between two approximately perpendicular walls of described exemplary gap in low-K material.In other embodiments, in low-K material, do not form step, only form single approximately perpendicular wall.In disclosed execution mode, described single vertical wall can depart from vertical 10 °, 5 ° or 2 °.In disclosed execution mode, before ashing (or after the processing that proposes here), the dielectric constant of low-K material can be less than 3.9,3.7,3.5,3.3 or 3.1.Dielectric constant is that the concentration by the carbon in the low K layer of silicon oxide carbide determines to a great extent.According to the embodiment of the present invention, after ashing, outside dielectric layer can have the dielectric constant greater than 3.0,3.2 or 3.5, and all the other low-k dielectric materials have respectively the dielectric constant less than 3.0,3.2 or 3.5.

After vapor phase etchant, can use optional step.The vapor phase etchant of just having described can stay the post-etch residues that comprises the part gas phase etchant.The existence of post-etch residues may with adjacent wires between electricity leak relevant.Described leakage for example can be caused by fluorine-containing post-etch residues.Therefore, the substrate after the etching can be flowed out the thing processing with plasma subsequently, leaks to remove some post-etch residues and to alleviate any electricity that may exist, and described plasma outflow thing comes from and comprises Ar, N ₂, NH ₃And H ₂In the plasma of one or more kinds.

During operating procedure 215, use the oxygen base to remove the photoresist 120 of filling the gap.The oxygen base generally is formed in the remote plasma body region, and flows to the substrate etching zone.In some embodiments, the oxygen base comprises neutral substance, and described neutral substance comprises elemental oxygen (O) and ozone (O ₃) in one or more kinds.In etching area, can have some ionised species, yet ionised species is tending towards than non-ionic (neutrality) elemental oxygen and non-ionic ozone recombinant more quickly.In some embodiments, remote plasma than the plasma in the etching area more preferably has enough chance neutralizations to guarantee ionised species.In disclosed execution mode, the preferably opening from the remote plasma to the etching area and path are so that neutral atomic oxygen (O) advances to the substrate etching zone.In some embodiments, in order to make side wall passivation to reduce oxidation, SiF ₄Side by side flow with oxygen base (using remote plasma or etching area plasma).The dielectric constant of increase may still appear and show in the oxide regions of low-K material.Therefore, the structure that forms by this way still can be benefited from method disclosed herein.

The above has described and has been used for ashing and SiConi ^TMEtched split cavity.In an alternate embodiments, the order according to treatment step in same chamber is carried out these techniques, needn't remove patterned substrate from process chamber.In describing exemplary treatment system process, disclose extra vapor phase etchant processing parameter and processed details.

Exemplary treatment system

Fig. 3 is the partial cross sectional view that diagram can be carried out the exemplary process chamber 300 of embodiment of the present invention.In general, can will excite among ammonia and the Nitrogen trifluoride introducing remote plasma body region 361-363 and by plasma electrical source 346 by one or more openings 351.

In one embodiment, process chamber 300 comprises chamber main body 312, cap assemblies 302 and supporting component 310.Cap assemblies 302 is arranged on the upper end of chamber main body 312, supporting component 310 at least part of being arranged in the chamber main body 312.Process chamber 300 and related hardware are preferably formed by one or more kinds of process compatible materials (such as aluminium, stainless steel etc.).

Chamber main body 312 comprises the slit valve opening 360 in the sidewall that is formed on described chamber main body 312, and slit valve opening 360 is used for providing the entrance that enters process chamber 300 inside.Slit valve opening 360 optionally opens and closes by processing of wafers machinery hand (not shown), so that the entrance that enters chamber main body 312 inside to be provided.In one embodiment, wafer can be delivered into process chamber 300 or transfer out adjacent transfer chamber and/or load lock chamber from process chamber 300 by slit valve opening 360, or other chambers in the combination tool.Illustrate the example combinations instrument that can comprise process chamber 300 among Fig. 4.

In one or more execution modes, chamber main body 312 comprises be used to making heat-tranfer fluid flow through the chamber body passageways 313 of chamber main body 312.Described heat-tranfer fluid can be to add hot fluid or cooling agent, and described heat-tranfer fluid is used for the temperature in technique and substrate transfer process control room main body 312.The temperature of chamber main body 312 is for prevent assembling gas on chamber wall or byproduct is extremely important unexpectedly.Exemplary heat-tranfer fluid comprises water, ethylene glycol or both mixtures.Exemplary heat-tranfer fluid also can comprise nitrogen.Supporting component 310 can have supporting component passage 304, and described supporting component passage 304 is used for making heat-tranfer fluid flow through supporting component 310, affects thus base reservoir temperature.

Chamber main body 312 can further comprise the lining 333 that surrounds supporting component 310.Lining 333 is preferably removable, to be used for maintenance and to clean.Lining 333 can be by forming such as aluminium such metal or ceramic material.Yet lining 333 can be the material of any process compatible.Lining 333 can be through blasting treatment (bead blasted), is deposited on the caking property of any material on the described lining 333 with increase, prevents thus coming off of material, and described material comes off and causes process chamber 300 contaminated.In one or more execution modes, lining 333 is included in one or more openings 335 and the pump channel 329 that forms in the lining 333, and pump channel 329 carries out liquid communication with vacuum system.Opening 335 provides the stream that enters pump channel 329 for gas, and this provides outlet for the gas in the process chamber 300.

Vacuum system can comprise vacuum pump 325 and choke valve 327, to regulate the gas flow by process chamber 300.Vacuum pump 325 couples with the vacuum ports 331 that is arranged on the chamber main body 312, therefore carries out liquid communication with the pump channel 329 that is formed in the lining 333.Commutative use term " gas " and " multiple gases ", except as otherwise noted, above-mentioned term refers to the combination of one or more kinds of reactants, catalyst, carrier, cleanser, cleaning agent, above-mentioned substance, and any other introduces the fluid in the process chamber 312.Use term " precursor " to refer to and participate in reacting to remove from the surface or any process gas of deposition materials.

Opening 335 make pump channel 329 can with chamber main body 312 in processing region 340 carry out liquid communication.Processing region 340 is limited by the lower surface of cap assemblies 302 and the upper surface of supporting component 310, and processing region 340 is surrounded by lining 333.Opening 335 can be uniform-dimension and evenly spaced apart around lining 333.Yet, can use the opening of any quantity, position, size or shape, each of these design parameters can change according to the expectation flow pattern of gas on the substrate receiving surface, and the below will discuss in detail more.In addition, the size of opening 335, quantity and position configuration are left the Uniform Flow of the gas of process chamber 300 for realization.In addition, opening size and position can be configured to be provided fast or the pumping action of high power capacity, so that from process chamber 300 quick Exhaust Gas.For example, the quantity of the opening 335 of closely close vacuum ports 331 and size can be less than quantity and the sizes of the opening 335 that arranges away from vacuum ports 331.

Usually use gas to supply with panel (not shown), in order to process gas is provided for process chamber 300 by one or more openings 351.Employed specific gas or multiple gases depend on technique or the kinds of processes of carrying out in process chamber 300.Exemplary gas can comprise any mixture or the composition of (but being not limited to) one or more kinds of precursors, reducing agent, catalyst, carrier, cleanser, cleaning agent or above-mentioned substances.Usually, one or more kinds of gases of introducing process chamber 300 flow in the plasma space 361 by the opening 351 in the top board 350.Replaceable or in combination, process gas can more directly be introduced in the processing regions 340 by opening 352.Opening 352 has avoided remote plasma to excite, and for the technique that relates to the gas that does not need plasma exciatiaon or do not excite benefited technique of great use from additional gas.The active oxygen that produces in the remote plasma can be introduced in the processing region 340 by opening, and does not pass zone 361,362 and 363.Can make electricity consumption operated valve and/or mobile controlling organization (not shown), with control from the gas supply source to process chamber 300 gas flow.According to described technique, can carry any multiple gases to process chamber 300, and can in process chamber or before gas is transported to process chamber 300, mix these gases.

Cap assemblies 302 can further comprise electrode 345, and electrode 345 is at the plasma of cap assemblies 302 interior generation active materials.In one embodiment, electrode 345 is supported by top board 350, and electrode 345 is electrically insulated with top board 350 by inserting electrical insulation ring 347, and electrical insulation ring 347 is formed by the material of aluminium oxide or any other insulation and process compatible.In one or more execution modes, electrode 345 is coupled to power supply 346, and remaining cap assemblies 302 is connected with ground.Therefore, can be at the plasma of one or more kinds of process gass of remote plasma region generating, described remote plasma body region is comprised of the space 361 between electrode 345 and the annular mounting flange 322,362 and/or 363.In execution mode, annular mounting flange comprises or supports gas delivery board 320.For example, can between one or two stopper plate of electrode 345 and stopper assembly 330, introduce and keep plasma.Replacedly, when not having stopper assembly 330, can between electrode 345 and gas delivery board 320, produce and comprise plasma.In arbitrary execution mode, plasma is completely restricted or is included in the cap assemblies 302.Correspondingly, because the substrate in not having plasma active and being arranged on chamber main body 312 directly contacts, so plasma is " remote plasma ".As a result, because plasma separates with substrate surface, so can avoid plasma to the infringement of substrate.

Various power supplys 346 can excite ammonia and gas of nitrogen trifluoride and be active material.For example, can use discharge technology based on radio frequency (RF), direct current (DC) or microwave (MW).Described excite also can be by based on technology, gas dissociation technique, the high-intensity light source (for example UV energy) of heat or be exposed to the x radiographic source and produce.Perhaps, can use remote excitation source (such as the remote plasma generator) to produce the plasma of active material, the plasma of described active material is transported in the process chamber 300 subsequently.Exemplary remote plasma generator can obtain from manufacturer, and described manufacturer is such as MKS Instruments, Inc. and AdvancedEnergy Industries, Inc..In exemplary treatment system, the RF supply coupling is to electrode 345.High-Power Microwave power supply 346 is favourable in the situation that also will use power supply 346 generation active oxygens.

Can flow through respectively chamber body passageways 313 and supporting component passage 304 by making heat-transfer material, control each temperature of chamber body 312 and substrate.Can be at supporting component 301 interior formation supporting component passages 304, so that the transfer of heat energy.Chamber main body 312 and supporting component 310 can cool off separately or heat.For example, add hot fluid and can flow through in chamber main body 312 and the supporting component 310 one, and cooling fluid flows through in chamber main body 312 and the supporting component 310 another.

Can use additive method control base reservoir temperature.Can be by being heated by resistive device heating supporting component 310 (or the part of supporting component 310, such as base) or heating substrate by some other modes.In another configuration, gas delivery board 320 can maintain the temperature that is higher than substrate, and substrate is lifted, with the rising base reservoir temperature.In this case, substrate is by radiation heating, or heats substrate by using gas that heat is transmitted to substrate from gas delivery board 320.Substrate can be by rising supporting component 310 or by using the lifting bolt to be lifted.

Here during the described etch process, in different execution modes, chamber main body 312 can maintain between approximate 50 ℃ to 80 ℃, between 55 ℃ to 75 ℃ or in the temperature range between 60 ℃ to 70 ℃.During being exposed to plasma and flowing out thing and/or oxidant, in different execution modes, it is about below 100 ℃, about below 65 ℃, between about 15 ℃ and about 50 ℃ or between about 22 ℃ and about 40 ℃ that substrate can maintain.

Plasma flows out thing and comprises various molecules, molecule fragment and ionised species.Current welcome SiConi ^TMTheoretical mechanism may or may be not exclusively correct, be believed to comprise NH but plasma flows out thing ₄F and NH ₄F.HF, NH ₄F and NH ₄F.HF is easy to and low temperature substrates described herein reaction.Plasma flows out thing and can react with silicon oxide surface, to form product (NH ₄) ₂SiF ₆, NH ₃And H ₂O.NH ₃And H ₂O is gasifying liquid under the described treatment conditions herein, and can remove from processing region 340 by vacuum pump 325.(NH ₄) ₂SiF ₆Continuous or the discontinuous thin layer of solid by-product is stayed on the substrate surface.

Flow out thing and solid by-product and on groove (groove that comprises step) vertical wall, correspondingly after the accumulation, can heat substrate to remove byproduct when removing the film of relatively high K from low-K material, being exposed to plasma.In execution mode, by in gas delivery board 320 or near gas delivery board 320 combined heated elements 370, gas delivery board 320 is heatable.Can heat substrate by the distance between the gas delivery board that reduces substrate and heating.In different execution modes, gas delivery board 320 can be heated between about 100 ℃ and 150 ℃, between about 110 ℃ and 140 ℃, perhaps between about 120 ℃ and 130 ℃.By the spacing distance between the gas delivery board that reduces substrate and heating, in different execution modes, substrate can be heated to about more than 75 ℃, and is about more than 90 ℃, about more than 100 ℃ or between about 115 ℃ and about 150 ℃.The heat that is radiated substrate from gas delivery board 320 should be enough with suprabasil solid (NH ₄) ₂SiF ₆Separating or distilling is can be from the volatile products SiF of processing region 340 extractions ₄, NH ₃And HF.

In different execution modes, ammonia (or generally speaking, hydrogeneous precursor) can with at about 50sccm and approximately between the 300sccm, at about 75sccm and approximately between the 250sccm, about 100sccm and approximately between the 200sccm or about 120sccm and approximately the flow between the 170sccm flow in the remote plasma space 361.In different execution modes, Nitrogen trifluoride (or generally speaking, fluorine-containing precursor) can with at about 25sccm and approximately between the 150sccm, at about 40sccm and approximately between the 175sccm, about 50sccm and approximately between the 100sccm or about 60sccm and approximately the flow between the 90sccm flow in the remote plasma space 361.The combined flow that hydrogeneous and fluorine-containing precursor enters the remote plasma body region can account for whole gas mixed volume 0.05% to about 20%, all the other are vector gas.In one embodiment, cleanser or vector gas were introduced in first before those active gasess in the remote plasma body region, to stablize the pressure in the remote plasma body region.

By the remainder with respect to cap assemblies 302, apply energy of plasma for electrode 345,361,362 and/or 363 interior generation plasmas flow out the product of thing in the space.The plasma energy can be the combination of various frequencies or multi-frequency.In exemplary treatment system, provide plasma by the RF energy that flows to electrode 345.In different execution modes, described RF energy can be approximately between 1W and the about 1000W, approximately between 5W and the about 600W, at about 10W with approximately between the 300W or at about 20W with approximately between the 100W.The RF frequency of using in described exemplary treatment system can be less than about 200kHz in different execution modes, less than about 150kHz, less than about 120kHz or at about 50kHz with approximately between the 90kHz.

In the cineration technics process, can or be used for exciting the identical chamber (361-362) of etchant gasses to form active oxygen in the process chamber outside.In execution mode, active oxygen can comprise with more stable molecular oxygen (O ₂) elemental oxygen (O) and the ozone (O that flow together ₃), being combined in of these materials is called active oxygen here.The flow of active oxygen can be approximately between 1slm and the about 50slm, approximately between 2slm and the about 30slm or at about 5slm with approximately between the 10slm in different execution modes.The air-flow of active oxygen can be before entering processing region 340 by opening 352 and the air-flow combination of extra relevant inert gas (for example He, Ar).Comprise described relevant inert carrier and have multiple benefit, comprise the increase plasma density.

Processing region 340 can flow out logistics at ozone, oxygen, vector gas and/or plasma and advance in the process of processing region 340 to maintain under the various pressure.Described pressure can maintain in different execution modes between about 500 millitorrs and about 30 holders, between about 1 holder and about 10 holders or between about 3 holders and about 6 holders.Also can be in processing region 340 interior use low pressure.Described pressure can maintain about 500 millitorrs or following in different execution modes, about 250 millitorrs or following, about 100 millitorrs or following, about 50 millitorrs or following, perhaps about 20 millitorrs or following.

In one or more execution modes, process chamber 300 can be integrated into various multiprocessing platforms, comprises the Producer that can obtain from the Applied Materials in the Santa Clara city that is positioned at California, USA ^TMGT, Centura ^TMAP and Endura ^TMPlatform.This processing platform can destroy vacuum just can carry out multiple processing operation.

Fig. 4 is the schematic top view of exemplary multi-chamber treatment system 400.System 400 can comprise one or more load lock chambers 402,404, and described load lock chamber 402,404 is for substrate being shifted into or migrated out system 400.Usually, because system 400 is in vacuum, so load lock chamber 402,404 can carry out " suction " (pump down) to the substrate in the drawing-in system 400.The first manipulator 410 can be between load lock chamber 402,404 and first groups of one or more base treatment chambers 412,414,416,418 (illustrating four) transfer substrate.Each process chamber 412,414,416,418 can be by complete assembling to carry out a plurality of base treatment operations, described a plurality of base treatment operation is except comprising that circulation layer deposits (CLD), ald (ALD), chemical vapour deposition (CVD) (CVD), physical vapour deposition (PVD) (PVD), etching, prerinse, degassed, directed and other base process, also comprises dry etching process described herein.

The first manipulator 410 also can be transferred to substrate one or more transfer chambers 422,424, or migrates out substrate from one or more transfer chambers 422,424.Transfer chamber 422,424 is used in and makes substrate keep UHV condition in system's 400 interior transfers.The second manipulator 430 can be between transfer chamber 422,424 and second groups of one or more process chambers 432,434,436,438 transfer substrate.With process chamber 412,414,416,418 similar, process chamber 432,434,436,438 can be by complete assembling to carry out various base treatment operations, described various base treatment operational example as except comprise circulation layer deposition (CLD), ald (ALD), chemical vapour deposition (CVD) (CVD), physical vapour deposition (PVD) (PVD), etching, prerinse, degassed and directed, also comprise dry etching process described here.If optional for the special process that is undertaken by system 400, then can remove arbitrary base treatment chamber 412,414,416,418,432,434,436,438 from system 400.Before gas was transported to exemplary process chamber, gas can be provided by gas handling system 455, also mix along delivery pathways.

System controller 457 is used for control motor, valve, flow governor, power supply and carries out other required functions of processing step described here.System controller 457 can rely on the feedback of optical pickocff, to determine and to adjust the position of removable mechanical component.Mechanical component can comprise manipulator, choke valve and pedestal, said modules under the control of system controller 457 by motor removing.

In an exemplary execution mode, system controller 457 comprises hard disk drive (memory), USB port, floppy disk and processor.System controller 457 comprises analog-and digital-input/output board, interface board and controllor for step-by-step motor plate.The various piece that comprises the multi-chamber treatment system 400 of process chamber 300 is controlled by system controller 457.Described system controller is to be stored in the form executive system control software of the computer program on the computer-readable medium (such as hard disk, floppy disk or flash memory thumb actuator).Also can use the memory of other types.Computer program comprises the instruction group, during described instruction group indicating gage, other parameters of admixture of gas, chamber pressure, chamber temp, RF power level, base position and special process.

The technique that can use the computer program of being carried out by controller to implement to be used for the technique of deposited film in substrate or be used for wash chamber 15.Computer program code can be write with the readable programming language of any conventional computer: for example, and 68000 assembler languages, C, C++, Pascal, Fortran or other.Use conventional text editor that the program code that is fit to is input to Single document or a plurality of file, and described suitable program code is stored or is embedded in the computer usable medium, in the accumulator system such as computer.If the code text of input is high-level language, then compile described code, then with final compiled code and precompiler Microsoft

The object identification code of storehouse routine is linked.For the object identification code of the compiling of carrying out described link, system user calls described object identification code, make computer system with described code loading in memory.Then CPU reads and carries out described code, with the task of carrying out identifying in the described program.

Interface between user and the controller can pass through touch-sensitive display, and the interface between user and the controller also can comprise mouse and keyboard.In one embodiment, used two displays, display is installed in the clean room wall for the operator, and another display is positioned at the wall back for service technician.Only having a display to be configured in the situation of disposable reception input, described two displays can show identical information simultaneously.In order to select specific screen or function, the operator uses the appointed area on finger or the mouse touch display screen.The touch area changes the highlight color of touch area, perhaps shows new menu or screen, confirms thus operator's selection.

" substrate " used herein can be to form in the above or do not have a cambial support base.Support base can be insulator or the semiconductor with various doping contents and profile, and support base for example can be the semiconductor base of institute's type of service in the manufacturing of integrated circuit.Use " silica " layer as the simple expression that contains the silica material and can with contain silica material Alternate.Like this, silica can comprise the concentration of other elemental constituents, such as nitrogen, hydrogen, carbon etc.In some embodiments, silica is comprised of silicon and oxygen in fact.Gas in " excitation state " has been described a kind of like this gas, and in described gas, at least some gas molecules are in oscillatory excitation, separation and/or ionization state.Gas can be two or the combination of more kinds of gases.Use term " groove " and " gap " in the whole text, do not infer etched geometry and have larger level orientation ratio.When seeing from the surface, groove and gap can be rendered as circle, ellipse, polygon, rectangle or various other shapes.Use term " path " to refer to the groove (when viewed from above) of reduced levels orientation ratio, metal can be filled or can not filled to described groove to form vertical electrical connection.

Describe several execution modes, one skilled in the art will recognize that, in the situation of the spirit that does not break away from disclosed execution mode, can use structure and the equivalent of various modifications, replacement.In addition, for fear of the unnecessary indigestion of the present invention that makes, a plurality of techniques of knowing and element are not described.Therefore, top description should not thought and limits the scope of the invention.

When number range is provided, be to be understood that each median that also specifically discloses between described range limit and lower limit, up to 1/10th of lower limit unit, unless clearly explained other modes in the literary composition.Median in any setting or prescribed limit and each the less scope between any other setting or the median in described prescribed limit have been comprised.These upper and lower bounds among a small circle can independently comprise or be not included in the described scope, the present invention has also comprised wherein describedly comprising one of boundary value among a small circle, do not comprise boundary value or comprising each scopes of whole boundary values, is not included in the boundary value of any concrete eliminating in the described prescribed limit.When described prescribed limit comprises one or two boundary value, also comprised the scope of getting rid of these boundary values that comprise one or both of.

As using here with in the appended claims, singulative " " (" a ", " an ") and " described " (" the ") comprise that several refer to thing, unless clear other situations that represented in the literary composition.Thereby, for example, relate to " technique " and comprise and relate to several this technique, and relate to " described dielectric substance " and comprise and relate to one or more kinds of dielectric substances and known equivalent for those skilled in the art, etc.

In addition, term " comprises ", " comprising " and " containing " when using in described specification neutralization claims subsequently, mean to offer some clarification on and have described feature, integral body, assembly or step, exist or additional other features of one or more kinds, integral body, assembly, step, operation or group's group but do not get rid of.

Claims (15)

1. method that reduces the effective dielectric constant of low-k dielectric materials, described low-k dielectric materials is between two grooves on the patterned substrate, described patterned substrate is in basement processing area, and wherein said low-k dielectric materials consists of the wall of described two grooves, and described method comprises:

Described patterned substrate is transferred in the described basement processing area; With

Described patterned substrate is carried out vapor phase etchant, with by removing outside dielectric layer from described low-k dielectric materials, reduce the average dielectric constant of described low-k dielectric materials.

2. the method for claim 1, wherein said vapor phase etchant comprises:

Make fluorine-containing precursor and hydrogeneous precursor flow to the first remote plasma body region, described the first remote plasma body region and described basement processing area flow and couple, simultaneously in described the first remote plasma body region, form plasma, flow out thing to produce plasma;

Advance described basement processing area by making described plasma flow out logistics, the described patterned substrate of etching forms solid by-product on the surface of described substrate simultaneously; With

Be elevated to by the temperature that makes described substrate more than the sublimation temperature of described solid by-product, make described solid by-product distillation.

3. method as claimed in claim 2, wherein said fluorine-containing precursor comprises at least a precursor, described at least a precursor is selected from the group that is comprised of following material: the hydrocarbon that Nitrogen trifluoride, hydrogen fluoride, diatomic fluorine, monoatomic fluorine and fluorine replace.

4. method as claimed in claim 2, wherein said hydrogeneous precursor comprises at least a precursor, described at least a precursor is selected from the group that is comprised of following material: the hydrocarbon that atomic hydrogen, molecular hydrogen, ammonia, hydrocarbon and halogen not exclusively replace.

5. method as claimed in claim 2 wherein in the operating period of the described solid by-product of distillation, is elevated to about 100 ℃ or higher with the temperature of described substrate.

6. the method for claim 1, wherein said outside dielectric layer has the dielectric constant greater than 3.0, and remaining described low-k dielectric materials has the dielectric constant less than 3.0.

7. the method for claim 1, the relatively high dielectric constant of wherein said outside dielectric layer is caused by plasma ashing.

8. the method for claim 1 further is included in the operation of described patterned substrate being carried out before the operation of described vapor phase etchant ashing.

9. the method for claim 1, wherein the wall from described two grooves removes described outside dielectric layer.

10. the described operation of ashing wherein after the operation of described patterned substrate being transferred in the described basement processing area, occurs described patterned substrate is carried out in method as claimed in claim 8.

11. method as claimed in claim 8 wherein before the operation of described patterned substrate being transferred in the described basement processing area, occurs described patterned substrate is carried out the described operation of plasma ashing.

12. the method for claim 1, the thickness of wherein said outside dielectric layer is approximately 150

Or less.

13. the method for claim 1, wherein in the vapor phase etchant process, the etch-rate of described outside dielectric layer exceeds greater than 50 times than the etch-rate of remaining described low-k dielectric materials.

14. the method for claim 1, wherein described patterned substrate is carried out after the described operation of vapor phase etchant, and then in atmosphere described patterned substrate is carried out plasma treatment, to remove the residue after the etching, described atmosphere comprises argon gas, nitrogen (N ₂), ammonia (NH ₃) or hydrogen (H ₂) at least a.

15. method as claimed in claim 14, the residue after the wherein said etching comprises fluorine.

Images